Columella auris is a modified

$A$ bucket containing water is revolved in a vertical circle of radius $r$. To prevent the water from falling down, the minimum frequency of revolution required is $[g = \text{acceleration due to gravity}]$.

Which of the following hydrides has the lowest boiling point?

Which one of the following is more readily hydrolysed by $S_{N}1$ mechanism?

If $\alpha+\beta=-2$ and $\alpha^3+\beta^3=-56$,then the quadratic equation whose roots are $\alpha$ and $\beta$ is

If $\frac{x-4}{x^2-5x-2k} = \frac{2}{x-2} - \frac{1}{x+k}$,then $k$ is equal to